I've been dealing (or NOT dealing) with a slight fuel
smell inside my relatively stock 73'S since I bought it
in 89'. Sometimes stronger then other times, a little stronger with the window cracked just a bit, and getting a little stronger lately. This last weekend I went about finding this pain in the nose. With a tip
from a fellow Porsche nut I went directly to the 'fuel
overflow expansion box'. This is a black 3/3/6 thermo-
plastic box with two bungs on the bottom. The box lives behind the dash at about the location of the left gauge cluster, OR looking the other way, behind
the fresh air duct on the fuel side of the car. Low and
behold the box had sight cracks on the top and along
the tops seam. When covering one bung and blowing into the other with the box submerged in water bubbles appeared at these suspect areas. The box can be ordered
from Porsche (it stuck around till the end of the SC's) ... mine was not too bad so I 'welded' or remelted the bad areas back up with a soldering iron
then sealed them up with black weather strip adhesive
(almost NOTHING sticks to thermo-plastic) While I was
at it I also rehosed the complete overflow system. After a 'up to the top' fill up and a 'brisk' ride
through the hills, I have to say, this the first time
the old blue car has been COMPLETELY 'smelless' .....

For what it's worth .... Happy 'S-ing
Chuck Miller